Howdy Ray.....I don't know your radio specifically but would suggest
initially determining whether you are looking at a bad power circuit
connection which fails under transmit load OR whether there's an
abnormal heavy current condition occurring during transmit. Does the
receiver otherwise work ok? One place you might look is at any
switching contacts part of a connector for external power or for
external charging. I've found many times particularly with the coaxial
type power connectors that when they use a contact to disconnect the
radio during charging, that this will fail under load.

You didn't mention whether you experienced a heavy current condition
while testing with your bench supply so I tend to think the situation is
a poor connection. IF it seems that you're into a heavy current
condition during transmit, you might check for a shorted
stage....disconnect power at the final for example to isolate that and
work backwards.

Hope this helps get you started.

Gord VE1AJF

On Tue, 25 Apr 2006 21:52:18 GMT, G wrote:

Howdy Ray.....I don't know your radio specifically but would suggest
initially determining whether you are looking at a bad power circuit
connection which fails under transmit load OR whether there's an
abnormal heavy current condition occurring during transmit. Does the
receiver otherwise work ok?

Yes, all functions work fine except for the battery pull down problem.
If I pull the battery real quick and test it, it's not down for
voltage much and recovers to full voltage in a few minutes so maybe
the battery state LED display is just haywire. It has 2 transmit
settings, 1W and 5W. The 5W is good for about 5 seconds and then the
readout gives a blinking error and transmission stops. It does
transmit well enough to another unit across the yard on the 1W
setting.
It's difficult to get to the battery contacts as they are a recessed,
spring loaded affair and the external power is the typical 1/8" dodad
popular in miniaturization these days.

One place you might look is at any
switching contacts part of a connector for external power or for
external charging. I've found many times particularly with the coaxial
type power connectors that when they use a contact to disconnect the
radio during charging, that this will fail under load.

It's a waterproof hand held for use in salt water environments with
some type of brown paste on all the connections and pass throughs.

You didn't mention whether you experienced a heavy current condition
while testing with your bench supply so I tend to think the situation is
a poor connection. IF it seems that you're into a heavy current
condition during transmit, you might check for a shorted
stage....disconnect power at the final for example to isolate that and
work backwards.

No, I didn't see any indication of a big load. Usually the bench
supply will groan and the voltage meter dips if there's something
exciting about to happen.
Now that I have it open there really is nothing to test or fix or
examine inside- just a maze of surface mount resistors and a central
proprietary chip half the size of a postage stamp. Probably just good
for the CG weather channel now.

Hope this helps get you started.

Gord VE1AJF
Thanks, Gord.

quizzling wrote:
Yes, all functions work fine except for the battery pull down problem.
If I pull the battery real quick and test it, it's not down for
voltage much and recovers to full voltage in a few minutes so maybe
the battery state LED display is just haywire.

This sounds like normal behavior from a dying battery. NiCad, NiMH and
alkaine batteries all act this way.

Since it works for a few seconds, it's likely that the batteries have not
shorted or leaked. I built a good deep cycle discharger from a five volt
relay and a large (10 Ohm 10watt) resistor. The relay coil was in parallel
with the resistor, and it's contacts when activated connect them to the
battery.

A push button across the contacts to activate it and an LED with a current
limiting resistor completed the device.

You push the button and let the battery discharge. When the voltage gets
to low to keep the relay closed, it stops discharging but the battery does
not go too low to be damaged.

If it is a NiCad or NiMH battery a few charge discharge cycles should
bring it back to normal. This assumes that the batteries have not leaked
or been damaged in any other way.

Note that this should NEVER be done to lead-acid or Lithium batteries.

While many experts have claimed that NiCad and NiMH batteries do not
have a memory effect, I used to get lots of NiMH batteries or cell
phones as gifts when they were near dead. A few cycles in the reconditioner
and they were back to normal.

This is almost seven years later, and I'm still splitting the packs apart
and using them to rebuild ham radio battery packs.

Lithium Ion battery packs can be "fixed" by sitting overnight in a freezer,
but it has NEVER worked for me. Freezing ultrasonicly welded NiCad packs
makes them easy to split open and replace the batteries.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

On Thu, 27 Apr 2006 10:51:07 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

quizzling wrote:
Yes, all functions work fine except for the battery pull down problem.
If I pull the battery real quick and test it, it's not down for
voltage much and recovers to full voltage in a few minutes so maybe
the battery state LED display is just haywire.

This sounds like normal behavior from a dying battery. NiCad, NiMH and
alkaine batteries all act this way.

Right, but I get the same result from running it on a bench supply.

Since it works for a few seconds, it's likely that the batteries have not
shorted or leaked. I built a good deep cycle discharger from a five volt
relay and a large (10 Ohm 10watt) resistor. The relay coil was in parallel
with the resistor, and it's contacts when activated connect them to the
battery.

A push button across the contacts to activate it and an LED with a current
limiting resistor completed the device.

You push the button and let the battery discharge. When the voltage gets
to low to keep the relay closed, it stops discharging but the battery does
not go too low to be damaged.

If it is a NiCad or NiMH battery a few charge discharge cycles should
bring it back to normal. This assumes that the batteries have not leaked
or been damaged in any other way.

Great idea. thanks.

Note that this should NEVER be done to lead-acid or Lithium batteries.

While many experts have claimed that NiCad and NiMH batteries do not
have a memory effect, I used to get lots of NiMH batteries or cell
phones as gifts when they were near dead. A few cycles in the reconditioner
and they were back to normal.

This is almost seven years later, and I'm still splitting the packs apart
and using them to rebuild ham radio battery packs.

Lithium Ion battery packs can be "fixed" by sitting overnight in a freezer,
but it has NEVER worked for me. Freezing ultrasonicly welded NiCad packs
makes them easy to split open and replace the batteries.

Hmm, I have some power tool batteries I was wondering how to take
apart. Thanks.

Geoff.

ray lunder wrote:

(works for a few seconds and stops)

Right, but I get the same result from running it on a bench supply.

Where? The DC in jack may be only for a charger. In order to pass
saftey regulations, the current may be limited on the DC in jack.

This would prevent the radio from "blowing up" if water got into the
DC in jack and the batteries discharged through the radio very quickly.

For example, I once discussed the subject with the product manager of
a handheld GPS unit. I suggested that they make sure the battery charging
contacts where current limited so that shorting them would not cause damage
to the user or the battery. He had never heard of such things.

I was involved with the design of a handheld gaming device. We had
specificly designed it so that if the battery on the unit or a spare
in your pocket got wet or contacted keys or loose change, nothing bad
would happen.

I think it is safe to assume that while not everyone does this, some
companies do.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

On Fri, 28 Apr 2006 10:51:03 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

ray lunder wrote:

(works for a few seconds and stops)

Right, but I get the same result from running it on a bench supply.

Where? The DC in jack may be only for a charger. In order to pass
saftey regulations, the current may be limited on the DC in jack.

I removed the battery and hooked jumpers from the supply to the
battery contacts so there's no battery involved for the test.

This would prevent the radio from "blowing up" if water got into the
DC in jack and the batteries discharged through the radio very quickly.

For example, I once discussed the subject with the product manager of
a handheld GPS unit. I suggested that they make sure the battery charging
contacts where current limited so that shorting them would not cause damage
to the user or the battery. He had never heard of such things.

I was involved with the design of a handheld gaming device. We had
specificly designed it so that if the battery on the unit or a spare
in your pocket got wet or contacted keys or loose change, nothing bad
would happen.
Good idea.

I think it is safe to assume that while not everyone does this, some
companies do.

Geoff.
Thanks.

Just to follow up, inspired by your suggestion I flattened the battery
and charged for 18hrs. It works fine now. Thanks for your help.

On Sun, 30 Apr 2006 06:44:59 GMT, ray lunder wrote:

On Fri, 28 Apr 2006 10:51:03 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

ray lunder wrote:

(works for a few seconds and stops)

Right, but I get the same result from running it on a bench supply.

Where? The DC in jack may be only for a charger. In order to pass
saftey regulations, the current may be limited on the DC in jack.

I removed the battery and hooked jumpers from the supply to the
battery contacts so there's no battery involved for the test.

This would prevent the radio from "blowing up" if water got into the
DC in jack and the batteries discharged through the radio very quickly.

For example, I once discussed the subject with the product manager of
a handheld GPS unit. I suggested that they make sure the battery charging
contacts where current limited so that shorting them would not cause damage
to the user or the battery. He had never heard of such things.

I was involved with the design of a handheld gaming device. We had
specificly designed it so that if the battery on the unit or a spare
in your pocket got wet or contacted keys or loose change, nothing bad
would happen.
Good idea.

I think it is safe to assume that while not everyone does this, some
companies do.

Geoff.
Thanks.